TECHNICAL FIELD
[0001] Aspects of the present disclosure relate generally to wireless communication systems,
and more particularly, to scheduling resources for user equipment (UE) sidelink communication.
Certain embodiments of the technology discussed below can enable and provide scheduling
of resources for a sidelink between a first UE in communication with a base station
and a specified second UE in communication with the first UE, such as using downlink
control information (DCI) and/or radio resource control (RRC) signaling.
INTRODUCTION
[0003] Wireless communication networks are widely deployed to provide various communication
services such as voice, video, packet data, messaging, broadcast, and the like. These
wireless networks may be multiple-access networks capable of supporting multiple users
by sharing the available network resources. Such networks, which are usually multiple
access networks, support communications for multiple users by sharing the available
network resources.
[0004] A wireless communication network may include a number of base stations or node Bs
that can support communication for a number of user equipments (UEs). A UE may communicate
with a base station via downlink and uplink. The downlink (or forward link) refers
to the communication link from the base station to the UE, and the uplink (or reverse
link) refers to the communication link from the UE to the base station.
[0005] A base station may transmit data and control information on the downlink to a UE
and/or may receive data and control information on the uplink from the UE. On the
downlink, a transmission from the base station may encounter interference due to transmissions
from neighbor base stations or from other wireless radio frequency (RF) transmitters.
On the uplink, a transmission from the UE may encounter interference from uplink transmissions
of other UEs communicating with the neighbor base stations or from other wireless
RF transmitters. This interference may degrade performance on both the downlink and
uplink.
[0006] The UEs may comprise various device configurations, such as a mobile wireless device,
an Internet of Things (IoT) or Internet of Everything (IoE) device, etc., and may
have particular associated communication needs and/or requirements. For example, latency
and reliability requirements for Industrial Internet of Things (IIoT) traffic are
stringent (e.g., latency ≈ 1-2ms and reliability ≈ 10
-5-10
-6 block error rate (BLER)). The aforementioned interference presents challenges with
respect to some wireless communications meeting needs and/or requirements of the particular
wireless devices and situations.
SUMMARY
[0007] The scope of the present invention is defined in the appended independent claims
1, 6, 7 and 9. Specific embodiments of the present invention are defined in the dependent
claims.
[0008] The following summarizes some aspects of the present disclosure to provide a basic
understanding of the discussed technology. This summary is not an extensive overview
of all contemplated features of the disclosure and is intended neither to identify
key or critical elements of all aspects of the disclosure nor to delineate the scope
of any or all aspects of the disclosure. Its sole purpose is to present some concepts
of one or more aspects of the disclosure in summary form as a prelude to the more
detailed description that is presented later.
[0009] In one aspect of the disclosure, a method of wireless communication is provided.
The method may include scheduling resources for a sidelink between a first user equipment
(UE) and a specified second UE. The first UE may be in communication with a base station
and may be a UE to transmit to the specified second UE via the sidelink. The method
may also include transmitting control signaling to the first UE to implement the sidelink
between the first UE and the specified second UE in accordance with the scheduling.
The control signaling may be configured to identify the specified second UE.
[0010] In an additional aspect of the disclosure, an apparatus configured for wireless communication
is provided. The apparatus may include means for scheduling resources for a sidelink
between a first UE and a specified second UE. The first UE may be in communication
with a base station and may be a UE to transmit to the specified second UE via the
sidelink. The apparatus may also include means for transmitting control signaling
to the first UE to implement the sidelink between the first UE and the specified second
UE in accordance with the scheduling. The control signaling may be configured to identify
the specified second UE.
[0011] In an additional aspect of the disclosure, a non-transitory computer-readable medium
having program code recorded thereon for wireless communication is provided. The program
code may include code to schedule resources for a sidelink between a first UE and
a specified second UE. The first UE may be in communication with a base station and
may be a UE to transmit to the specified second UE via the sidelink. The program code
may also include code to transmit control signaling to the first UE to implement the
sidelink between the first UE and the specified second UE in accordance with the scheduling.
The control signaling may be configured to identify the specified second UE.
[0012] In an additional aspect of the disclosure, an apparatus configured for wireless communication
is provided. The apparatus includes at least one processor, and a memory coupled to
the processor. The processor may be configured to schedule resources for a sidelink
between a first UE and a specified second UE. The first UE may be in communication
with the base station and may be a UE to transmit to the specified second UE via the
sidelink. The processor may also be configured to transmit control signaling to the
first UE to implement the sidelink between the first UE and the specified second UE
in accordance with the scheduling. The control signaling may be configured to identify
the specified second UE.
[0013] In accordance with aspects of the disclosure, the foregoing systems, methods, and
apparatuses may be implemented in combination with one or more additional features,
such as the following features whether alone or in combination. For example, the above
systems, methods, and apparatuses may include the control signaling including downlink
control information (DCI). The above systems, methods, and apparatuses may include
the DCI being according to DCI format 3_0. The above systems, methods, and apparatuses
may include controlling resources allocated to the sidelink between the first UE and
the specified second UE using the DCI. The above systems, methods, and apparatuses
may include determining if additional resource allocation is to be provided for the
sidelink between the first UE and the specified second UE based at least in part on
an acknowledgment/negative-acknowledgment (ACK/NACK) received from the first UE via
a physical uplink control channel (PUCCH). The above systems, methods, and apparatuses
may include the DCI being configured to carry a sidelink receiver UE indicator. The
above systems, methods, and apparatuses may include a field being included in the
DCI to carry the sidelink receiver UE indicator. The above systems, methods, and apparatuses
may include a field of the DCI being repurposed to carry the sidelink receiver UE
indicator. The above systems, methods, and apparatuses may include the sidelink receiver
UE indicator including an index value corresponding to the specified second UE to
indicate the specified second UE as a receiver UE for the sidelink. The above systems,
methods, and apparatuses may include configuring a mapping from an identification
of the specified second UE to the index value via radio resource control (RRC) signaling.
The above systems, methods, and apparatuses may include the scheduling being with
respect to a dynamic grant (DG), and scrambling a cyclic redundancy check (CRC) of
the DCI using a sidelink-radio network temporary identifier (SL-RNTI) corresponding
to the first UE. The above systems, methods, and apparatuses may include the scheduling
being with respect to a configured grant (CG), and scrambling a CRC of the DCI using
a sidelink-configured scheduling-radio network temporary identifier (SL-CS-RNTI) corresponding
to the first UE. The above systems, methods, and apparatuses may include associating,
by the base station, one or more hybrid automatic repeat request (HARQ) process identifiers
with the specified second UE. The above systems, methods, and apparatuses may include
the DCI carrying the one or more HARQ process identifiers to identify the specified
second UE as a receiver UE for the sidelink. The above systems, methods, and apparatuses
may include the associating the one or more HARQ process identifiers with the specified
second UE leaving at least one HARQ process identifier unassociated with any particular
sidelink receiver UE. The above systems, methods, and apparatuses may include scrambling
a CRC of the DCI based at least in part on an identifier corresponding to the specified
second UE. The above systems, methods, and apparatuses may include the scheduling
being with respect to a DG, and the scrambling the CRC of the DCI including scrambling
the CRC using a sidelink-transmitter UE-receiver UE-radio network temporary identifier
(SL-TX-RX-RNTI) corresponding to the first UE and the specified second UE. The above
systems, methods, and apparatuses may include distributing the SL-TX-RX-RNTI to the
first UE via RRC signaling. The above systems, methods, and apparatuses may include
the scheduling being with respect to a CG, and scrambling the CRC of the DCI including
scrambling the CRC using a sidelink-configured scheduling-transmitter UE-receiver
UE-radio network temporary identifier (SL-CS-TX-RX-RNTI) corresponding to the first
UE and the specified second UE. The above systems, methods, and apparatuses may include
distributing the SL-CS-TX-RX-RNTI to the first UE via RRC signaling. The above systems,
methods, and apparatuses may include the scheduling being with respect to a CG, and
the control signaling including RRC signaling. The above systems, methods, and apparatuses
may include configuring the first UE for the sidelink via the RRC signaling using
an identification of the specified second UE.
[0014] In one aspect of the disclosure, a method of wireless communication is provided.
The method may include receiving control signaling scheduling resources for a sidelink
between a first UE and a specified second UE. The first UE may be in communication
with a base station and may be a UE to transmit to the specified second UE via the
sidelink. The control signaling may be configured to identify the specified second
UE. The method may also include implementing, based on the control signaling, the
sidelink between the first UE and the specified second UE in accordance with the scheduling.
[0015] In an additional aspect of the disclosure, an apparatus configured for wireless communication
is provided. The apparatus may include means for receiving control signaling scheduling
resources for a sidelink between a first UE and a specified second UE. The first UE
may be in communication with a base station and may be a UE to transmit to the specified
second UE via the sidelink. The control signaling may be configured to identify the
specified second UE. The apparatus may also include means for implementing, based
on the control signaling, the sidelink between the first UE and the specified second
UE in accordance with the scheduling.
[0016] In an additional aspect of the disclosure, a non-transitory computer-readable medium
having program code recorded thereon for wireless communication is provided. The program
code may include code to receive control signaling scheduling resources for a sidelink
between a first UE and a specified second UE. The first UE may be in communication
with a base station and may be a UE to transmit to the specified second UE via the
sidelink. The control signaling may be configured to identify the specified second
UE. The program code may also include code to implement, based on the control signaling,
the sidelink between the first UE and the specified second UE in accordance with the
scheduling.
[0017] In an additional aspect of the disclosure, an apparatus configured for wireless communication
is provided. The apparatus includes at least one processor, and a memory coupled to
the processor. The processor may be configured to receive control signaling scheduling
resources for a sidelink between a first UE and a specified second UE. The first UE
may be in communication with a base station and may be a UE to transmit to the specified
second UE via the sidelink. The control signaling may be configured to identify the
specified second UE. The processor may also be configured to implement, based on the
control signaling, the sidelink between the first UE and the specified second UE in
accordance with the scheduling.
[0018] In accordance with aspects of the disclosure, the foregoing systems, methods, and
apparatuses may be implemented in combination with one or more additional features,
such as the following features whether alone or in combination. For example, the above
systems, methods, and apparatuses may include the control signaling including DCI.
The above systems, methods, and apparatuses may include the DCI being according to
DCI format 3_0. The above systems, methods, and apparatuses may include the first
UE operating under control of the base station to implement resources allocated to
the sidelink between the first UE and the specified second UE as designated by the
DCI. The above systems, methods, and apparatuses may include providing, via a PUCCH,
an ACK/NACK configured for the base station determining if additional resource allocation
is to be provided for the sidelink between the first UE and the specified second UE.
The above systems, methods, and apparatuses may include the DCI being configured to
carry a sidelink receiver UE indicator. The above systems, methods, and apparatuses
may include a field being included in the DCI to carry the sidelink receiver UE indicator.
The above systems, methods, and apparatuses may include a field of the DCI being repurposed
to carry the sidelink receiver UE indicator. The above systems, methods, and apparatuses
may include the sidelink receiver UE indicator including an index value corresponding
to the specified second UE to indicate the specified second UE as a receiver UE for
the sidelink. The above systems, methods, and apparatuses may include receiving a
mapping from an identification of the specified second UE to the index value via RRC
signaling. The above systems, methods, and apparatuses may include the scheduling
being with respect to a DG, and a CRC of the DCI being scrambled using a sidelink-radio
network temporary identifier (SL-RNTI) corresponding to the first UE. The above systems,
methods, and apparatuses may include the scheduling being with respect to a CG, and
a CRC of the DCI being scrambled using a SL-CS-RNTI corresponding to the first UE.
The above systems, methods, and apparatuses may include one or more HARQ process identifiers
being associated with the specified second UE, and the DCI carrying the one or more
HARQ process identifiers to identify the specified second UE as a receiver UE for
the sidelink. The above systems, methods, and apparatuses may include at least one
HARQ process identifier remaining unassociated with any particular sidelink receiver
UE. The above systems, methods, and apparatuses may include a CRC of the DCI being
scrambled based at least in part on an identifier corresponding to the specified second
UE. The above systems, methods, and apparatuses may include the scheduling being with
respect to a DG, and the CRC being scrambled using a SL-TX-RX-RNTI corresponding to
the first UE and the specified second UE. The above systems, methods, and apparatuses
may include receiving the SL-TX-RX-RNTI via radio resource control (RRC) signaling.
The above systems, methods, and apparatuses may include the scheduling being with
respect to a CG, and the CRC being scrambled using a SL-CS-TX-RX-RNTI corresponding
to the first UE and the specified second UE. The above systems, methods, and apparatuses
may include receiving the SL-CS-TX-RX-RNTI via RRC signaling. The above systems, methods,
and apparatuses may include the scheduling being with respect to a CG, and the control
signaling including RRC signaling. The above systems, methods, and apparatuses may
include receiving an identification of the specified second UE via the RRC signaling
for configuring the first UE for the sidelink.
[0019] Other aspects, features, and embodiments will become apparent to those of ordinary
skill in the art, upon reviewing the following description of specific, exemplary
embodiments in conjunction with the accompanying figures. While features may be discussed
relative to certain aspects and figures below, all embodiments can include one or
more of the advantageous features discussed herein. In other words, while one or more
aspects may be discussed as having certain advantageous features, one or more of such
features may also be used in accordance with the various aspects. In similar fashion,
while exemplary aspects may be discussed below as device, system, or method aspects,
the exemplary aspects can be implemented in various devices, systems, and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A further understanding of the nature and advantages of the present disclosure may
be realized by reference to the following drawings. In the appended figures, similar
components or features may have the same reference label. Further, various components
of the same type may be distinguished by following the reference label by a dash and
a second label that distinguishes among the similar components. If just the first
reference label is used in the specification, the description is applicable to any
one of the similar components having the same first reference label irrespective of
the second reference label.
FIG. 1 is a block diagram illustrating details of a wireless communication system.
FIG. 2 is a block diagram conceptually illustrating a design of a base station and
a UE.
FIG. 3 is a diagram illustrating the deterministic and periodic nature of industrial
Internet of things (IIoT) traffic.
FIG. 4 is a portion of a wireless network forming an industrial environment control
network.
FIG. 5 is a physical-layer procedure flow for sidelink resource grants in accordance
with V2X interface DG/CG Type 2 protocols.
FIGS. 6 and 7 are flow diagrams of operation providing scheduling of resources for
a sidelink between a first UE in communication with a base station and a specified
second UE in communication with the first UE.
FIG. 8 is a block diagram conceptually illustrating a design of a base station configured
to provide scheduling with respect to a sidelink between a first UE and a specified
second UE.
FIG. 9 is a block diagram conceptually illustrating a design of a UE configured to
implement scheduling with respect to a sidelink between the UE and a specified second
UE
DETAILED DESCRIPTION
[0021] The detailed description set forth below, in connection with the appended drawings,
is intended as a description of various configurations and is not intended to limit
the scope of the disclosure. Rather, the detailed description includes specific details
for the purpose of providing a thorough understanding of the inventive subject matter.
It will be apparent to those skilled in the art that these specific details are not
required in every case and that, in some instances, well-known structures and components
are shown in block diagram form for clarity of presentation.
[0022] This disclosure relates generally to providing or participating in authorized shared
access between two or more wireless devices in one or more wireless communications
systems, also referred to as wireless communications networks. In various implementations,
the techniques and apparatus may be used for wireless communication networks such
as code division multiple access (CDMA) networks, time division multiple access (TDMA)
networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA)
networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5
th Generation (5G) or new radio (NR) networks (sometimes referred to as "5G NR" networks/systems/devices),
as well as other communications networks. As described herein, the terms "networks"
and "systems" may be used interchangeably.
[0023] A CDMA network, for example, may implement a radio technology such as universal terrestrial
radio access (UTRA), cdma2000, and the like. UTRA includes wideband-CDMA (W-CDMA)
and low chip rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards.
[0024] A TDMA network may, for example implement a radio technology such as Global System
for Mobile Communication (GSM). The Third Generation Partnership Project (3GPP) defines
standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network
(RAN), also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with
the network that joins the base stations (for example, the Ater and Abis interfaces)
and the base station controllers (A interfaces, etc.). The radio access network represents
a component of a GSM network, through which phone calls and packet data are routed
from and to the public switched telephone network (PSTN) and Internet to and from
subscriber handsets, also known as user terminals or user equipments (UEs). A mobile
phone operator's network may comprise one or more GERANs, which may be coupled with
Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network.
Additionally, an operator network may also include one or more LTE networks, and/or
one or more other networks. The various different network types may use different
radio access technologies (RATs) and radio access networks (RANs).
[0025] An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA),
IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and
Global System for Mobile Communications (GSM) are part of universal mobile telecommunication
system (UMTS). In particular, long term evolution (LTE) is a release of UMTS that
uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from
an organization named "3
rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from
an organization named "3
rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards
are known or are being developed. For example, the 3GPP is a collaboration between
groups of telecommunications associations that aims to define a globally applicable
third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is
a 3GPP project which was aimed at improving the universal mobile telecommunications
system (UMTS) mobile phone standard. The 3GPP may define specifications for the next
generation of mobile networks, mobile systems, and mobile devices. The present disclosure
may describe certain aspects with reference to LTE, 4G, or 5G NR technologies; however,
the description is not intended to be limited to a specific technology or application,
and one or more aspects described with reference to one technology may be understood
to be applicable to another technology. Indeed, one or more aspects of the present
disclosure are related to shared access to wireless spectrum between networks using
different radio access technologies or radio air interfaces.
[0026] 5G networks contemplate diverse deployments, diverse spectrum, and diverse services
and devices that may be implemented using an OFDM-based unified, air interface. To
achieve these goals, further enhancements to LTE and LTE-A are considered in addition
to development of the new radio technology for 5G NR networks. The 5G NR will be capable
of scaling to provide coverage (1) to a massive Internet of Things (IoTs) with an
ultra-high density (e.g., ~1M nodes/km2), ultra-low complexity (e.g., ~10s of bits/sec),
ultra-low energy (e.g., ~10+ years of battery life), and deep coverage with the capability
to reach challenging locations; (2) including mission-critical control with strong
security to safeguard sensitive personal, financial, or classified information, ultra-high
reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~ 1 millisecond
(ms)), and users with wide ranges of mobility or lack thereof; and (3) with enhanced
mobile broadband including extreme high capacity (e.g., ~ 10 Tbps/km2), extreme data
rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates), and deep awareness
with advanced discovery and optimizations.
[0027] 5G NR devices, networks, and systems may be implemented to use optimized OFDM-based
waveform features. These features may include scalable numerology and transmission
time intervals (TTIs); a common, flexible framework to efficiently multiplex services
and features with a dynamic, low-latency time division duplex (TDD)/frequency division
duplex (FDD) design; and advanced wireless technologies, such as massive multiple
input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced
channel coding, and device-centric mobility. Scalability of the numerology in 5G NR,
with scaling of subcarrier spacing, may efficiently address operating diverse services
across diverse spectrum and diverse deployments. For example, in various outdoor and
macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing
may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth.
For other various outdoor and small cell coverage deployments of TDD greater than
3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz bandwidth. For other
various indoor wideband implementations, using a TDD over the unlicensed portion of
the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth.
Finally, for various deployments transmitting with mmWave components at a TDD of 28
GHz, subcarrier spacing may occur with 120 kHz over a 500MHz bandwidth.
[0028] The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and
quality of service (QoS) requirements. For example, shorter TTI may be used for low
latency and high reliability, while longer TTI may be used for higher spectral efficiency.
The efficient multiplexing of long and short TTIs to allow transmissions to start
on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe
design with uplink/downlink scheduling information, data, and acknowledgement in the
same subframe. The self-contained integrated subframe supports communications in unlicensed
or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly
configured on a per-cell basis to dynamically switch between uplink and downlink to
meet the current traffic needs.
[0029] For clarity, certain aspects of the apparatus and techniques may be described below
with reference to example 5G NR implementations or in a 5G-centric way, and 5G terminology
may be used as illustrative examples in portions of the description below; however,
the description is not intended to be limited to 5G applications.
[0030] Moreover, it should be understood that, in operation, wireless communication networks
adapted according to the concepts herein may operate with any combination of licensed
or unlicensed spectrum depending on loading and availability. Accordingly, it will
be apparent to a person having ordinary skill in the art that the systems, apparatus
and methods described herein may be applied to other communications systems and applications
than the particular examples provided.
[0031] While aspects and implementations are described in this application by illustration
to some examples, those skilled in the art will understand that additional implementations
and use cases may come about in many different arrangements and scenarios. Innovations
described herein may be implemented across many differing platform types, devices,
systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses
may come about via integrated chip embodiments and/or other non-module-component based
devices (e.g., end-user devices, vehicles, communication devices, computing devices,
industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices,
etc.). While some examples may or may not be specifically directed to use cases or
applications, a wide assortment of applicability of described innovations may occur.
Implementations may range from chip-level or modular components to non-modular, non-chip-level
implementations and further to aggregated, distributed, or OEM devices or systems
incorporating one or more described aspects. In some practical settings, devices incorporating
described aspects and features may also necessarily include additional components
and features for implementation and practice of claimed and described embodiments.
It is intended that innovations described herein may be practiced in a wide variety
of implementations, including both large/small devices, chip-level components, multicomponent
systems (e.g. RF-chain, communication interface, processor), distributed arrangements,
end-user devices, etc. of varying sizes, shapes, and constitution.
[0032] FIG. 1 is a block diagram illustrating details of an example wireless communication
system. The wireless communication system may include wireless network 100. Wireless
network 100 may, for example, include a 5G wireless network. As appreciated by those
skilled in the art, components appearing in FIG. 1 are likely to have related counterparts
in other network arrangements including, for example, cellular-style network arrangements
and non-cellular-style-network arrangements (e.g., device to device or peer to peer
or ad hoc network arrangements, etc.).
[0033] Wireless network 100 illustrated in FIG. 1 includes a number of base stations 105
and other network entities. A base station may be a station that communicates with
the UEs and may also be referred to as an evolved node B (eNB), a next generation
eNB (gNB), an access point, and the like. Each base station 105 may provide communication
coverage for a particular geographic area. In 3GPP, the term "cell" can refer to this
particular geographic coverage area of a base station and/or a base station subsystem
serving the coverage area, depending on the context in which the term is used. In
implementations of wireless network 100 herein, base stations 105 may be associated
with a same operator or different operators (e.g., wireless network 100 may include
a plurality of operator wireless networks). Additionally, in implementations of wireless
network 100 herein, base station 105 may provide wireless communications using one
or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum,
unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples,
an individual base station 105 or UE 115 may be operated by more than one network
operating entity. In some other examples, each base station 105 and UE 115 may be
operated by a single network operating entity.
[0034] A base station may provide communication coverage for a macro cell or a small cell,
such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally
covers a relatively large geographic area (e.g., several kilometers in radius) and
may allow unrestricted access by UEs with service subscriptions with the network provider.
A small cell, such as a pico cell, would generally cover a relatively smaller geographic
area and may allow unrestricted access by UEs with service subscriptions with the
network provider. A small cell, such as a femto cell, would also generally cover a
relatively small geographic area (e.g., a home) and, in addition to unrestricted access,
may also provide restricted access by UEs having an association with the femto cell
(e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the
like). A base station for a macro cell may be referred to as a macro base station.
A base station for a small cell may be referred to as a small cell base station, a
pico base station, a femto base station or a home base station. In the example shown
in FIG. 1, base stations 105d and 105e are regular macro base stations, while base
stations 105a-105c are macro base stations enabled with one of 3 dimension (3D), full
dimension (FD), or massive MIMO. Base stations 105a-105c take advantage of their higher
dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth
beamforming to increase coverage and capacity. Base station 105f is a small cell base
station which may be a home node or portable access point. A base station may support
one or multiple (e.g., two, three, four, and the like) cells.
[0035] Wireless network 100 may support synchronous or asynchronous operation. For synchronous
operation, the base stations may have similar frame timing, and transmissions from
different base stations may be approximately aligned in time. For asynchronous operation,
the base stations may have different frame timing, and transmissions from different
base stations may not be aligned in time. In some scenarios, networks may be enabled
or configured to handle dynamic switching between synchronous or asynchronous operations.
[0036] UEs 115 are dispersed throughout the wireless network 100, and each UE may be stationary
or mobile. It should be appreciated that, although a mobile apparatus is commonly
referred to as user equipment (UE) in standards and specifications promulgated by
the 3GPP, such apparatus may additionally or otherwise be referred to by those skilled
in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber
unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless
communications device, a remote device, a mobile subscriber station, an access terminal
(AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal,
a user agent, a mobile client, a client, a gaming device, an augmented reality device,
vehicular component device/module, or some other suitable terminology. Within the
present document, a "mobile" apparatus or UE need not necessarily have a capability
to move, and may be stationary. Some non-limiting examples of a mobile apparatus,
such as may include implementations of one or more of UEs 115, include a mobile, a
cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a
wireless local loop (WLL) station, a laptop, a personal computer (PC), a notebook,
a netbook, a smart book, a tablet, and a personal digital assistant (PDA). A mobile
apparatus may additionally be an "Internet of Things" (IoT) or "Internet of Everything"
(IoE) device such as an automotive or other transportation vehicle, a satellite radio,
a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter,
a quad-copter, a smart energy or security device, a solar panel or solar array, municipal
lighting, water, or other infrastructure; industrial automation and enterprise devices;
consumer and wearable devices, such as eyewear, a wearable camera, a smart watch,
a health or fitness tracker, a mammal implantable device, gesture tracking device,
medical device, a digital audio player (e.g., MP3 player), a camera, a game console,
etc.; and digital home or smart home devices such as a home audio, video, and multimedia
device, an appliance, a sensor, a vending machine, intelligent lighting, a home security
system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal
Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does
not include a UICC. In some aspects, UEs that do not include UICCs may also be referred
to as IoE devices. UEs 115a-115d of the implementation illustrated in FIG. 1 are examples
of mobile smart phone-type devices accessing wireless network 100 A UE may also be
a machine specifically configured for connected communication, including machine type
communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. UEs
115e-115k illustrated in FIG. 1 are examples of various machines configured for communication
that access wireless network 100.
[0037] A mobile apparatus, such as UEs 115, may be able to communicate with any type of
the base stations, whether macro base stations, pico base stations, femto base stations,
relays, and the like. In FIG. 1, a communication link (represented as a lightning
bolt) indicates wireless transmissions between a UE and a serving base station, which
is a base station designated to serve the UE on the downlink and/or uplink, or desired
transmission between base stations, and backhaul transmissions between base stations.
UEs may operate as base stations or other network nodes in some scenarios. Backhaul
communication between base stations of wireless network 100 may occur using wired
and/or wireless communication links.
[0038] In operation at wireless network 100, base stations 105a-105c serve UEs 115a and
115b using 3D beamforming and coordinated spatial techniques, such as coordinated
multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul
communications with base stations 105a-105c, as well as small cell, base station 105f.
Macro base station 105d also transmits multicast services which are subscribed to
and received by UEs 115c and 115d. Such multicast services may include mobile television
or stream video, or may include other services for providing community information,
such as weather emergencies or alerts, such as Amber alerts or gray alerts.
[0039] Wireless network 100 of implementations supports mission critical communications
with ultra-reliable and redundant links for mission critical devices, such UE 115e,
which is a drone. Redundant communication links with UE 115e include from macro base
stations 105d and 105e, as well as small cell base station 105f. Other machine type
devices, such as UE 115f (thermometer), UE 115g (smart meter), UE 115h (wearable device),
UE 115m (robotic actuator), and UE 115n (industrial controller) may communicate through
wireless network 100 either directly with base stations, such as small cell base station
105f, and macro base station 105e, or in multi-hop configurations by communicating
with another user device which relays its information to the network, such as UE 115f
communicating temperature measurement information to the industrial controller, UE
115n, which may utilize the data and/or report the data to the network (e.g., for
transmission to another device, such as another industrial controller) through small
cell base station 105f. Wireless network 100 may also provide additional network efficiency
through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle
(V2V) or vehicle-to-everything (V2X) mesh network between UEs 115i-115k communicating
with macro base station 105e.
[0040] FIG. 2 shows a block diagram conceptually illustrating an example design of a base
station 105 and a UE 115, which may be any of the base stations and one of the UEs
in FIG. 1. For a restricted association scenario (as mentioned above), base station
105 may be small cell base station 105f in FIG. 1, and UE 115 may be UE 115c or 115D
operating in a service area of base station 105f, which in order to access small cell
base station 105f, would be included in a list of accessible UEs for small cell base
station 105f. Base station 105 may also be a base station of some other type. As shown
in FIG. 2, base station 105 may be equipped with antennas 234a through 234t, and UE
115 may be equipped with antennas 252a through 252r for facilitating wireless communications.
[0041] At base station 105, transmit processor 220 may receive data from data source 212
and control information from controller/processor 240. The control information may
be for the physical broadcast channel (PBCH), physical control format indicator channel
(PCFICH), physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH),
physical downlink control channel (PDCCH), enhanced physical downlink control channel
(EPDCCH), MTC physical downlink control channel (MPDCCH), etc. The data may be for
the PDSCH, etc. Additionally, transmit processor 220 may process (e.g., encode and
symbol map) the data and control information to obtain data symbols and control symbols,
respectively. Transmit processor 220 may also generate reference symbols, e.g., for
the primary synchronization signal (PSS) and secondary synchronization signal (SSS),
and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO)
processor 230 may perform spatial processing (e.g., precoding) on the data symbols,
the control symbols, and/or the reference symbols, if applicable, and may provide
output symbol streams to modulators (MODs) 232a through 232t. For example, spatial
processing performed on the data symbols, the control symbols, or the reference symbols
may include precoding. Each modulator 232 may process a respective output symbol stream
(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may additionally
or alternatively process (e.g., convert to analog, amplify, filter, and upconvert)
the output sample stream to obtain a downlink signal. Downlink signals from modulators
232a through 232t may be transmitted via antennas 234a through 234t, respectively.
[0042] At UE 115, the antennas 252a through 252r may receive the downlink signals from base
station 105 and may provide received signals to demodulators (DEMODs) 254a through
254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert,
and digitize) a respective received signal to obtain input samples. Each demodulator
254 may further process the input samples (e.g., for OFDM, etc.) to obtain received
symbols. MIMO detector 256 may obtain received symbols from demodulators 254a through
254r, perform MIMO detection on the received symbols if applicable, and provide detected
symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode)
the detected symbols, provide decoded data for UE 115 to data sink 260, and provide
decoded control information to controller/processor 280.
[0043] On the uplink, at UE 115, transmit processor 264 may receive and process data (e.g.,
for the physical uplink shared channel (PUSCH)) from data source 262 and control information
(e.g., for the physical uplink control channel (PUCCH)) from controller/processor
280. Additionally, transmit processor 264 may also generate reference symbols for
a reference signal. The symbols from transmit processor 264 may be precoded by TX
MIMO processor 266 if applicable, further processed by modulators 254a through 254r
(e.g., for SC-FDM, etc.), and transmitted to base station 105. At base station 105,
the uplink signals from UE 115 may be received by antennas 234, processed by demodulators
232, detected by MIMO detector 236 if applicable, and further processed by receive
processor 238 to obtain decoded data and control information sent by UE 115. Processor
238 may provide the decoded data to data sink 239 and the decoded control information
to controller/processor 240.
[0044] Controllers/processors 240 and 280 may direct the operation at base station 105 and
UE 115, respectively. Controller/processor 240 and/or other processors and modules
at base station 105 and/or controller/processor 280 and/or other processors and modules
at UE 115 may perform or direct the execution of various processes for the techniques
described herein, such as to perform or direct the execution illustrated in FIGS.
6 and 7, and/or other processes for the techniques described herein. Memories 242
and 282 may store data and program codes for base station 105 and UE 115, respectively.
Scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.
[0045] Wireless communications systems operated by different network operating entities
(e.g., network operators) may share spectrum. In some instances, a network operating
entity may be configured to use an entirety of a designated shared spectrum for at
least a period of time before another network operating entity uses the entirety of
the designated shared spectrum for a different period of time. Thus, in order to allow
network operating entities use of the full designated shared spectrum, and in order
to mitigate interfering communications between the different network operating entities,
certain resources (e.g., time) may be partitioned and allocated to the different network
operating entities for certain types of communication.
[0046] For example, a network operating entity may be allocated certain time resources reserved
for exclusive communication by the network operating entity using the entirety of
the shared spectrum. The network operating entity may also be allocated other time
resources where the entity is given priority over other network operating entities
to communicate using the shared spectrum. These time resources, prioritized for use
by the network operating entity, may be utilized by other network operating entities
on an opportunistic basis if the prioritized network operating entity does not utilize
the resources. Additional time resources may be allocated for any network operator
to use on an opportunistic basis.
[0047] Access to the shared spectrum and the arbitration of time resources among different
network operating entities may be centrally controlled by a separate entity, autonomously
determined by a predefined arbitration scheme, or dynamically determined based on
interactions between wireless nodes of the network operators.
[0048] In some cases, UE 115 and base station 105 may operate in a shared radio frequency
spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency
spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum
band, UEs 115 or base stations 105 may traditionally perform a medium-sensing procedure
to contend for access to the frequency spectrum. For example, UE 115 or base station
105 may perform a listen-before-talk or listen-before-transmitting (LBT) procedure
such as a clear channel assessment (CCA) prior to communicating in order to determine
whether the shared channel is available. In some implementations, a CCA may include
an energy detection procedure to determine whether there are any other active transmissions.
For example, a device may infer that a change in a received signal strength indicator
(RSSI) of a power meter indicates that a channel is occupied. Specifically, signal
power that is concentrated in a certain bandwidth and exceeds a predetermined noise
floor may indicate another wireless transmitter. A CCA also may include detection
of specific sequences that indicate use of the channel. For example, another device
may transmit a specific preamble prior to transmitting a data sequence. In some cases,
an LBT procedure may include a wireless node adjusting its own backoff window based
on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge
(ACK/NACK) feedback for its own transmitted packets as a proxy for collisions.
[0049] In an example implementation of wireless network 100, one or more of UEs 115 may
comprise various forms of IoT devices, such as industrial Internet of things (IIoT)
devices, in communication via wireless links of wireless network 100. For example,
the IIoT devices of some deployments may comprise sensors (e.g., position sensors,
temperature sensors, pressure sensors, power sensors, motion detectors, proximity
detectors, accelerometers, scanners, cameras, probes, switches, etc.) and/or actuators
(e.g., linear actuators, rotary actuators, servomechanisms, solenoids, stepper motors,
electric motors, comb drive actuators, etc.). A large number of IIoT devices may be
in communication with a corresponding device, such as an industrial controller (e.g.,
computer, programmable logic controller (PLC), supervisory control and data acquisition
(SCADA) system, etc.), of a control network in an industrial environment, such as
a manufacturing facility, materials processing facility, warehouse, etc. For example,
a PLC may be in communication with 20-50 sensors and/or actuators, wherein 100-1000
such PLCs may be deployed throughout an industrial (e.g., manufacturing) facility.
[0050] The various IIoT devices of an industrial environment control network may periodically
communicate information (e.g., measurements, state information, command acknowledgments,
etc.) to and/or receive information (e.g., commands, parameters, settings, state information,
etc.) from an associated industrial controller. For example, cyclic exchanges may
be performed between an industrial controller and a large number of IIoT devices of
a control network. Accordingly, the IIoT traffic may be deterministic and periodic,
as represented in the diagram of FIG. 3.
[0051] Latency and reliability requirements for IIoT traffic are often stringent since output
results typically must be produced in response to input conditions within a limited
time to avoid unintended, and even dangerous, operation of an industrial process.
For example, latency requirements of IIoT traffic may be on the order of 1-2ms and
the reliability requirements may be on the order of 10-5-10-6 block error rate (BLER).
Accordingly, both data and control channels of an industrial environment control network
may be designed to meet these overall requirements.
[0052] Control networks in industrial environments have traditionally utilized wireline
communication links. For example, IIoT devices may be in communication with a corresponding
industrial controller using wired network links, such as 100 base T Ethernet links.
Such a control network may be quite complicated with respect to establishing and maintaining
the network links, reconfiguring the network, etc. For example, the task of reconfiguring
a control network including a large number of IIoT devices deployed on a factory floor
can be costly in both time and expense.
[0053] There is interest in making industrial environment control network connectivity wireless.
Industrial environment control networks utilizing wireless links may, for example,
reduce the time and expense required for reconfiguration of the control network on
the factory floor. However, establishing and maintaining reliable wireless links between
an industrial controller and the IIoT devices associated therewith can be problematic.
For example, the industrial controllers are generally located close to machinery which
may cause issues (e.g., shadowing, electrical noise, etc.) in maintaining a reliable
and adequate communication link with ones of the many IIoT devices of the control
network. Moreover, the latency and reliability requirements for IIoT traffic can prove
challenging to meet in a wireless control network implementation.
[0054] In accordance with aspects of the present disclosure, one or more base stations are
utilized in an industrial environment control network, such as for aiding in multi-hop
communication links between industrial controllers and/or respective IIoT devices
of the control network. For example, one or more base stations 105 of wireless network
100 may be ceiling-mounted, or otherwise disposed (e.g., wall-mounted, mounted atop
a pole other structure, etc.), to provide a substantially unobstructed path to one
or more industrial controllers, some or all IIoT devices of a control network, etc.
The example of FIG. 4 shows a portion of wireless network 100 forming industrial environment
control network 400 in which base station 105f (e.g., small cell base station) is
disposed to aid with respect to communication links with respect to multiple UEs (shown
as UEs 115f, 115m, and 115n) of the control network.
[0055] Although an example of FIG. 4 is described as an industrial environment control network
400 in which UE 105f comprises a small cell configuration, UE 115n comprises a PLC
configuration, UE 115f comprises a thermometer sensor configuration, and UE 115m comprises
a robotic actuator configuration, this example configuration is merely illustrative
of a control network in which concepts of the present invention may be applied. It
should be appreciated that a control network may comprise various configurations of
both base stations (e.g., macro cells, small cells, etc., or combinations thereof),
industrial controller UEs, (e.g., computers, PLCs, SCADAs, etc., or combinations thereof),
and/or IIoT devices (e.g., position sensors, temperature sensors, pressure sensors,
power sensors, motion detectors, proximity detectors, accelerometers, scanners, cameras,
probes, switches, linear actuators, rotary actuators, servomechanism, solenoid, stepper
motor, electric motor, comb drive actuators, etc., or combinations thereof). Moreover,
although the example of FIG. 4 illustrates a single instance of a base station, a
single instance of an industrial controller, and two instances of IIoT devices for
simplicity, a control environment in which concepts of the present invention may be
implemented may comprise different numbers of any or all of the foregoing (e.g., multiple
base stations, multiple industrial controllers, and IIoT devices on the order of tens,
hundreds, or even thousands).
[0056] In the example of FIG. 4, UE 115n may comprise a PLC or other industrial controller
providing control functionality with respect to a plurality of sensor and actuator
IIoT devices (shown as including UEs 115f and 115m designated as sensor/actuator (S/A)
1 and S/A 2). UE 115n may communicate directly with base station 105f, such as using
a UE to UMTS (Uu) interface. UE 115n (e.g., industrial controller) may implement sidelinks
(i.e., communication links directly between UEs) with respect to UEs 115f (e.g., thermometer)
and 115m (e.g., robotic actuator), such as using a UE to UE interface (e.g., a PC5
interface of a V2X mesh network). Multi-hop communication may be provided between
UEs 115m and 115f and base station 105f via UE 115n. Base station 105f may additionally
or alternatively establish direct communication links with various ones of the IIoT
devices of a control network (e.g., UE 115f, UE 115m, etc.), such as using a Uu interface.
[0057] Existing V2X interface protocols provide for dynamic and configured grants for sidelinks
(e.g., a physical sidelink control channel (PSCCH) and/or physical sidelink shared
channel) using a PC5 interface. A dynamic grant (DG) may provide a one-time grant
of sidelink resources, such as responsive to instantaneous demand/need for sidelink
communication. A configured grant (CG) may provide a grant of sidelink resources enabling
continued/periodic/repeated sidelink communication. A first type of sidelink resource
grant (Type 1) of the V2X interface protocols uses radio resource control (RRC) to
configure a UE with resources of a CG. A second type of sidelink resource grant (Type
2) of the V2X interface protocols uses downlink control information (DCI) over a PDCCH
to configure a UE with resources of a DG or a CG. For example, the DCI may be a DG
and provide allocation of resources to be used for sidelink communication. Alternatively,
the DCI may be a CG and activate/deactivate a CG for sidelink communication.
[0058] FIG. 5 illustrates a physical-layer procedure flow (procedure flow 500) for sidelink
resource grants in accordance with the above mentioned V2X interface DG/CG Type 2
protocols. Procedure flow 500 of FIG. 5 is described with reference to a V2X mesh
network between UEs 115j and 115k communicating with macro base station 105e, as shown
in wireless network 100 of FIG. 1. It should be understood, however, that the procedure
flow may be implemented with respect to various UEs and UE configurations.
[0059] In procedure flow 500 of FIG. 5, base station 105e uses DCI, provided according to
DCI format 3_0 and which is configured to correspond to UE 115k (e.g., sidelink transmitter
(TX) UE), to deliver a DG/CG Type 2 to UE 115k at procedure 501. DCI format 3_0 provides
fields for time gap, hybrid automatic repeat request (HARQ) process identification,
new data indicator, lowest index of the subchannel allocation to the initial transmission,
first-stage sidelink control information (SCI) format 0-1 fields (including frequency
resource assignment and time resource assignment), physical sidelink feedback channel
(PSFCH) to HARQ feedback timing indicator, and PUCCH resource indicator, as well as
configuration index in the case of CG. Base station 105e prepares the DCI with a sidelink-radio
network temporary identifier (SL-RNTI) for UE 115, in the case of DG, or sidelink-configured
scheduling-radio network temporary identifier (SL-CS-RNTI) for UE 115k, in the case
of CG, to configure the DCI to correspond to UE 115k. In particular, the cyclic redundancy
check (CRC) of the DCI is scrambled by SL-RNTI or SL-CS-RNTI for UE 115K in order
to deliver a DG/CG Type 2 to the UE (e.g., sidelink TX UE).
[0060] In the case of CG, UE 115k (e.g., sidelink TX UE) reports the activation (or deactivation)
of a sidelink (not shown in procedure flow 500). In particular, activation/deactivation
of a CG sidelink is reported through media access control-control element (MAC-CE).
MAC-CE reporting is also used by UE 115k to provide sidelink buffer status reports
(BSRs) to base station 105e. For example, UE 115k may have provided a BSR indicating
data for sidelink communication is contained in the UE buffer, resulting in base station
115e initiating the sidelink resource grant of procedure 501.
[0061] At procedure 502 of procedure flow 500, UE 115k (e.g., sidelink TX UE) uses SCI,
provided according to SCI format 0-1 (e.g., for scheduling physical sidelink shared
channel (PSSCH) and second-stage SCI on PSSCH) and SCI format 0-2 (e.g., for decoding
PSSCH) to schedule PSSCH and transmits data through PSSCH to UE 115j (e.g., sidelink
receiver (RX) UE) according to the DG/CG Type 2 (sidelink resource grant of procedure
501). SCI format 0-1 provides fields for priority, frequency resource assignment,
time resource assignment, resource reservation period, demodulation reference signal
(DMRS) pattern, second-stage SCI format (broadcast, unicast, groupcast), Beta_offset
indicator, number of DMRS port, modulation and coding scheme (MCS), and a reserved
field. SCI format 0-2 provides fields for HARQ process identification, new data indicator,
redundancy version, source identification, destination identification, and channel
state information (CSI) request, also if the second-stage SCI format field in the
corresponding SCI provided in SCI format 0-1 indicates type 1 groupcast zone identification
and communication range requirement fields are present. MCS selection is up to the
sidelink TX UE (e.g., UE 115k in procedure flow 500), within limits set by the base
station (e.g., base station 105e).
[0062] It can be seen from the foregoing that the base station schedules node resources
for the sidelink TX UE (procedure 501) and the sidelink TX UE implements one or more
sidelinks with sidelink RX UEs using some or all of the scheduled resources (procedure
502). However, the base station does not control how the sidelink TX UE uses the resources
and which UEs are selected as the sidelink RX UEs by the sidelink TX UE. The existing
V2X protocols do not enable a base station making a sidelink resource grant to a sidelink
TX UE to schedule sidelink resources for a specific sidelink (e.g., a sidelink between
that sidelink TX UE and a specified sidelink RX UE).
[0063] Continuing with procedure flow 500 of FIG. 5, UE 115j (e.g., sidelink RX UE) provides
sidelink feedback to UE 115k (e.g., sidelink TX UE) at procedure 503. In particular,
UE 115j sends ACK/NACK on PSFCH upon receiving each transmission according to DG/CG
Type 2.
[0064] At procedure 504 of procedure flow 500, UE 115k (e.g., sidelink TX UE) forwards the
sidelink feedback provided by UE 115j (e.g., sidelink RX UE) to base station 105e.
In particular, UE 115k forwards the ACK/NACK received from UE 115j to base station
105e on PUCCH.
[0065] As discussed above with reference to FIG. 3, IIoT traffic exchanged between an industrial
controller and its corresponding IIoT devices is typically deterministic and periodic.
Also as discussed above, low latency communication is expected with respect to the
IIoT traffic. Accordingly, V2X protocols implementing DG/CG of sidelink resources
may be used with respect to IIoT traffic between an IIoT device and a corresponding
industrial controller in an attempt to enable low-latency communications. However,
although a base station may utilize V2X protocols to schedule resources for a first
UE (e.g., sidelink TX UE, such as UE 115k) to implement a sidelink with one or more
other UEs (e.g., sidelink RX UEs, such as UE 115j), the base station does not control
how the first UE (e.g., sidelink TX UE) uses the resources and which other UEs comprise
the second UEs (e.g., sidelink RX UEs). That is, a base station using existing V2X
interface protocols to provide sidelink resource grants (e.g., DGs or CGs) cannot
schedule resources for a specific sidelink (e.g., schedule resources for a sidelink
between a sidelink TX UE and a specified RX UE). For example, SL-RNTI and SL-CS-RNTI
used in respective DG and CG Type 2 are source-node (e.g., sidelink TX UE) specific
in the current PC5 interface. The DCI whose CRC is scrambled by SL-RNTI or SL-CS-RNTI
is sent to the sidelink TX UE only.
[0066] In accordance with aspects of the present disclosure, a base station is enabled to
schedule link resources, rather than node resources, with respect to sidelinks. For
example, a base station may schedule resources for a sidelink between a first UE (e.g.,
sidelink TX UE) in communication with a base station and a specified second UE (e.g.,
sidelink RX UE) in communication with the first UE. A base station may schedule resources
for a specific sidelink via DCI, using DCI format 3_0 or a hybrid thereof, such as
to provide DG and CG Type 2. According to some aspects of the disclosure, unlike operation
according to existing V2X protocols, a sidelink TX UE may be denied the freedom to
assign the granted resources to an arbitrary sidelink it controls. Instead, a sidelink
TX UE of embodiments follows the base station instruction indicated in the sidelink
resource grant (e.g., DCI) to allocate the resources to the corresponding sidelink
(e.g., sidelink between the sidelink TX UE and a specified sidelink RX UE). Such specific
sidelink scheduling of resources may be used to control, reduce, minimize, etc. link-level
interferences such as inter-cell interference and cross-link interference introduced
by sidelinks. For example, a base station may fully control the resources allocated
to a specific sidelink to enhance reliability through minimizing link-level interferences.
Additionally, in accordance with some aspects of the disclosure, a base station may
use an ACK/NACK, forwarded by a sidelink TX UE from a sidelink RX UE on PUCCH, to
determine if additional resource allocation is needed or otherwise advantageous for
a specific sidelink. For example, a base station may determine if additional resource
allocation is to be provided for the sidelink between the first UE and the specified
second UE based at least in part on an ACK/NACK received from the first UE (e.g.,
via PUCCH) in light of the ACK/NACK corresponding to a specific sidelink (e.g., a
sidelink between the first UE and the specified second UE).
[0067] A first UE that is in communication with a base station is referred to as a sidelink
TX UE in light of that UE initially establishing the sidelink, such as by transmitting
SCI and/or other information to the second UE of the sidelink. Correspondingly, a
specified second UE that is in communication with the first UE via a sidelink is referred
to as a sidelink RX UE in light of that UE initially receiving SCI and/or other information
transmitted by the first UE of the sidelink. It should be appreciated, however, that
UEs communicating via a sidelink implemented in accordance with aspects of the present
disclosure are not restricted or otherwise limited to the foregoing designated transmitter
or receiver roles. For example, bidirectional communication may be implemented between
a first UE and a specified second UE of a particular sidelink. Moreover, the specified
second UE may operate to primarily transmit via the sidelink, while the first UE may
operate to primarily receive via the sidelink, in some scenarios.
[0068] It should be appreciated that a grant with respect to sidelink resources identifying
a specified second UE according to some embodiments of the disclosure may identify
one or more second UEs. For example, a plurality of second UEs may be specified using
destination identification for a group of UEs forming the plurality of second UEs.
Additionally or alternatively, a plurality of second UEs may be specified using destination
identification information for each such UE.
[0069] FIGS. 6 and 7 show operation providing scheduling of resources for a sidelink between
a first UE in communication with a base station and a specified second UE in communication
with the first UE according to some embodiments of the present disclosure. In particular,
flow 600 of FIG. 6 illustrates operation by a base station with respect to scheduling
resources for UE sidelink communication in accordance with aspects of the disclosure.
Flow 700 of FIG. 7 illustrates operation by a UE (e.g., sidelink TX UE) with respect
to scheduling resources for UE sidelink communication in accordance with aspects of
the disclosure.
[0070] Referring first to the base station operation of flow 600 of FIG. 6, at block 601,
a base station schedules resources for a sidelink between a first UE and a specified
second UE. In accordance with embodiments, the first UE (e.g., sidelink TX UE) is
in communication with the base station and is a UE to transmit to the specified second
UE (e.g., specified sidelink RX UE) via the sidelink. Sidelink scheduling logic (e.g.,
logic implemented by program code, as may be stored in one or more memories such as
memory 242, executed by one or more controller/processors, such as controller/processor
240) of a base station (e.g., base station 105f of FIG. 1) may analyze various aspects
(e.g., UE locations/relative positions, frequency resources being used, timing resources
being used, CSI, buffer states, retransmission metrics, interference, transmission
power levels, receive signal strength information, etc.) to determine one or more
aspects (e.g., frequency resource assignment, time resource assignment, etc.) of scheduling
with respect to a sidelink between the first UE (e.g., UE 115n) and the specified
second UE (e.g., a specific one of UEs 115f and 115m). Such analysis may, for example,
identify sidelink resources suitable for scheduling with respect to the sidelink in
order to control, reduce, minimize, etc. link-level interferences (e.g., inter-cell
interference and/or cross-link interference) introduced by the sidelink.
[0071] At block 602 of flow 600, the base station transmits control signaling to the first
UE to implement the sidelink between the first UE and the specified second UE in accordance
with the scheduling. For example, wireless communication resources (e.g., one or more
wireless radios, such as may comprise modulator/demodulators 232a-t, MIMO detector
236, receive processor 238, transmit processor 220, and TX MIMO processor 230, operating
under control of one or more controller/processors, such as controller/processor 240
executing sidelink scheduling logic) of a base station (e.g., base station 105f) may
be utilized to transmit sidelink scheduling control signaling (e.g., comprising DCI
and/or RRC signaling) configured to provide scheduling of resources for a sidelink
between the first UE the specified second UE. In accordance with aspects of the disclosure,
the control signaling is configured to identify the specified second UE. For example,
a base station (e.g., base station 105f of FIG. 1) may schedule resources for a specific
sidelink by providing control signaling for implementing the sidelink between the
first UE (e.g., UE 115n) and the specified second UE (e.g., a specific one of UEs
115f and 115m) that is configured to identify or otherwise specify the second UE.
[0072] In a scenario where the sidelink resource grant is in accordance with a DG Type 2
or a CG Type 2, the control signaling may comprise DCI. For example, the DCI may be
provided according to DCI format 3_0 or a hybrid thereof (e.g., configured to carry
a sidelink receiver UE indicator, repurposing one or more fields, etc.).
[0073] In accordance with some aspects of the disclosure, DCI used with respect to scheduling
a sidelink between a first UE and a specified second UE may carry destination identification
for the specified second UE (e.g., the DCI carries a sidelink RX UE indicator). For
example, a field may be added in the payload of DCI format 3_0 to include destination
identification identifying the specified second UE for a sidelink. Additionally or
alternatively, a field of the DCI may be repurposed to carry the sidelink receiver
UE indicator (e.g., the configuration index field provided for CG Type 2 may be repurposed
as a destination identification field for DG Type 2 and/or for CG Type 2). The destination
identification may, for example, comprise actual or full destination identification
information (e.g., obtained from a destination identification database available to
the base station) for a specified second UE for a sidelink. In accordance with some
embodiments, the destination identification may be provided in the form of an index
value (e.g., an index value mapped to actual or full destination identification information,
as may be stored as part of a destination identification database) corresponding to
the specified second UE to indicate the specified second UE as a receiver UE for the
sidelink. A base station (e.g., base station 105f) may, for example, configure one
or more UEs (e.g., UEs 115f, 115m, 115n, etc.) with a mapping from an identification
of specific UEs (e.g., putative specified second UEs) to corresponding index values
via RRC signaling, such as when the UE joins wireless network 100, when the UE establishes
a link with the base station, when a sidelink communication feature is enabled with
respect to the UE, etc.
[0074] Embodiments utilizing destination identification carried by a field added to or repurposed
in the DCI format may prepare the DCI with RNTI corresponding to the first UE (e.g.,
sidelink TX UE). For example, in a case in which the scheduling is with respect to
a DG, the CRC of the DCI may be scrambled using a SL-RNTI corresponding to the first
UE. In a case in which the scheduling is with respect to a CG, the CRC of the DCI
may be scrambled using a SL-CS-RNTI corresponding to the first UE.
[0075] In accordance with some aspects of the disclosure, one or more HARQ process identifiers
may additionally or alternatively be associated with specific UEs (e.g., putative
specified second UEs, wherein associations between HARQ process identifiers and corresponding
UEs may be stored in a destination identification database available to the base station).
For example, HARQ process identifiers 0-3 may be assigned to or otherwise associated
with UE1 (e.g., UE 115f), HARQ process identifiers 4-7 may be assigned to or otherwise
associated with UE2 (e.g., UE 115m), etc. Some HARQ process identifiers may be left
for general purpose (e.g., unassigned or otherwise associated with specific UEs) use,
such as for use with respect to communications which the base station does not control.
DCI used with respect to scheduling a sidelink between a first UE and a specified
second UE may carry the one or more HARQ process identifiers to identify the specified
second UE as a receiver UE for the sidelink (e.g., the DCI carries HARQ process identifiers
providing a sidelink RX UE indicator).
[0076] Embodiments utilizing destination identification carried by HARQ process identifiers
associated with a sidelink RX UE may prepare the DCI with RNTI corresponding to the
first UE (e.g., sidelink TX UE). For example, in a case in which the scheduling is
with respect to a DG, the CRC of the DCI may be scrambled using a SL-RNTI corresponding
to the first UE. In a case in which the scheduling is with respect to a CG, the CRC
of the DCI may be scrambled using a SL-CS-RNTI corresponding to the first UE.
[0077] In accordance with some aspects of the disclosure, a CRC of the DCI may be scrambled
based at least in part on destination identification (e.g., obtained from a destination
identification database available to the base station) corresponding to the specified
second UE (e.g., the DCI carries CRC providing a sidelink RX UE indicator). For example,
the destination identification may essentially be carried in RNTI used for DCI. In
a case in which the scheduling is with respect to a DG, the CRC may be scrambled using
a sidelink-transmitter UE-receiver UE-radio network temporary identifier (SL-TX-RX-RNTI)
corresponding to the first UE (e.g., sidelink TX UE, such as UE 115n) and the specified
second UE (e.g., sidelink RX UE, such as UE 115f or UE 115m). In a case in which the
scheduling is with respect to a CG, the CRC may be scrambled using a sidelink-configured
scheduling-transmitter UE-receiver UE-radio network temporary identifier (SL-CS-TX-RX-RNTI)
corresponding to the first UE (e.g., sidelink TX UE, such as UE 115n) and the specified
second UE (e.g., sidelink RX UE, such as UE 115f or UE 115m). Accordingly, a base
station may use DCI provided in a DCI format 3_0 whose CRC is scrambled by SL-TX-RX-RNTI
or SL-CS-TX-RX-RNTI to grant a sidelink TX UE resources for the sidelink specified
by the RNTI. A base station (e.g., base station 105f) may distribute RNTI corresponding
to a sidelink RX UE (e.g., SL-TX-RX-RNTI and/or SL-CS-TX-RX-RNTI) to a sidelink TX
UE via RRC signaling, such as when the UE joins wireless network 100, when the UE
establishes a link with the base station, when a sidelink communication feature is
enabled with respect to the UE, etc. In accordance with aspects of the disclosure,
a base station may distribute N SL-TX-RX-RNTI and/or N SL-CS-TX-RX-RNTI to each sidelink
TX UE with N sidelink RX UEs.
[0078] In a scenario where the sidelink resource grant is in accordance with a CG Type 1,
the control signaling may comprise RRC. In operation according to CG Type 1, DCI provided
according to DCI format 3_0 is not used, and instead sidelink resources are automatically
activated when configured. Embodiments scheduling resources for a sidelink between
a first UE and a specified second UE may implement RRC signaling using destination
identification for the specified second UE. For example, a base station (e.g., base
station 105f) may provide RRC signaling to a first UE (e.g., sidelink TX UE, such
as UE 115n) to configure the first UE for sidelink communication with a specified
second UE (e.g., sidelink RX UE, such as UE 115f or 115m). The destination identification
(e.g., obtained from a destination identification database available to the base station)
may, for example, comprise actual or full destination identification information for
a specified second UE for a sidelink. In accordance with some embodiments, the destination
identification may be provided in the form of an index value (e.g., an index value
mapped to actual or full destination identification information) corresponding to
the specified second UE to indicate the specified second UE as a receiver UE for the
sidelink. A base station (e.g., base station 105f) may, for example, configure one
or more UEs (e.g., UEs 115f, 115m, 115n, etc.) with a mapping from an identification
of specific UEs (e.g., putative specified second UEs) to corresponding index values
via RRC signaling, such as when the UE joins wireless network 100, when the UE establishes
a link with the base station, when a sidelink communication feature is enabled with
respect to the UE, etc.
[0079] Referring now to the UE operation of flow 700 of FIG. 7, at block 701, a first UE
receives from a base station control signaling scheduling resources for a sidelink
between the first UE and a specified second UE. For example, wireless communication
resources (e.g., one or more wireless radios, such as may comprise modulator/demodulators
254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO
processor 266, operating under control of one or more controller/processors, such
as controller/processor 280 executing sidelink scheduling logic) of a UE (e.g., UE
115n) may be utilized to receive sidelink scheduling control signaling (e.g., comprising
DCI and/or RRC signaling) configured to provide scheduling of resources for a sidelink
between the first UE the specified second UE. The first UE (e.g., sidelink TX UE),
which is in communication with the base station, may be a UE to transmit to the specified
second UE (e.g., sidelink RX UE) via the sidelink. In accordance with aspects of the
disclosure, the control signaling is configured to identify the specified second UE.
For example, the control signaling may be configured (e.g., using a DCI field to carry
destination identification, using one or more HARQ process identifiers to provide
destination identification, RNTI used for DCI to provide destination identification,
or a combination thereof) to identify the specified second UE as described above with
respect to flow 600 of FIG. 6.
[0080] At block 702 of flow 700, the first UE implements, based on the control signaling,
the sidelink between the first UE and the specified second UE in accordance with the
scheduling. For example, sidelink scheduling logic (e.g., logic implemented by program
code, as may be stored in one or more memories such as memory 282, executed by one
or more controller/processors, such as controller/processor 280) of a UE (e.g., sidelink
TX UE, such as UE 115n of FIG. 1, receiving the sidelink grant) may analyze the sidelink
grant to identify a specified second UE (e.g., sidelink RX UE, such as UE 115f or
UE 115m), such as may be indicated by destination identification carried by or otherwise
determinable from the control signaling scheduling resources for a sidelink. Additional
information available to the first UE, such as information mapping from an identification
of specific UEs (e.g., putative specified second UEs) to corresponding index values
as may be stored in a destination identification database available to the first UE,
may be used in determining destination identification for the specified second UE
from the control signaling. The sidelink scheduling logic may additionally determine
the particular resources for the sideline between the first UE and the specified second
UE from the grant. Thus, the first UE may utilize this information to implement the
specific sidelink between the first UE (e.g., sidelink TX UE) and the specified second
UE (e.g., sidelink RX UE). For example, UE 115n (e.g., sidelink TX UE) may use SCI,
provided according to SCI format 0-1 (e.g., for scheduling physical sidelink shared
channel (PSSCH) and second-stage SCI on PSSCH) and SCI format 0-2 (e.g., for decoding
PSSCH) to schedule PSSCH and transmits data through PSSCH to UE 115f or UE 115m (e.g.,
specified second UE, sidelink RX UE) according to the DG/CG Type 2.
[0081] FIG. 8 is a block diagram illustrating base station 105 configured according to one
aspect of the present disclosure. Base station 105 includes the structure, hardware,
and components as illustrated for base station 105 of FIG. 2. For example, base station
105 includes controller/processor 240, which operates to execute logic or computer
instructions stored in memory 242, as well as controlling the components of base station
105 that provide the features and functionality of base station 105. Base station
105, under control of controller/processor 240, transmits and receives signals via
wireless radios 801a-t and antennas 234a-t. Wireless radios 801a-t include various
components and hardware, as illustrated in FIG. 2 for base station 105, including
modulator/demodulators 232a-t, MIMO detector 236, receive processor 238, transmit
processor 220, and TX MIMO processor 230.
[0082] Base station 105 of the example shown in FIG. 8 includes sidelink scheduling logic
802 and destination identification database 803 as may be utilized for performing
functions as described herein. Sidelink scheduling logic 802 may, for example, comprise
program code stored in memory 242 that is executed by controller/processor 240 for
providing respective functionality. Sidelink scheduling logic 802 may provide functionality
including scheduling resources for a sidelink between a first UE and a specified second
UE, controlling transmission of control signaling to the first UE to implement the
sidelink between the first UE and the specified second UE, etc., as may utilize destination
identification information from destination identification database 803, as described
above.
[0083] FIG. 9 is a block diagram illustrating UE 115 configured according to one aspect
of the present disclosure. UE 115 includes the structure, hardware, and components
as illustrated for UE 115 of FIG. 2. For example, UE 115 includes controller/processor
280, which operates to execute logic or computer instructions stored in memory 282,
as well as controlling the components of UE 115 that provide the features and functionality
of UE 115. UE 115, under control of controller/processor 280, transmits and receives
signals via wireless radios 901a-r and antennas 252a-r. Wireless radios 901a-r include
various components and hardware, as illustrated in FIG. 2 for UE 115, including modulator/demodulators
254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO
processor 266.
[0084] UE 115 of the example shown in FIG. 9 includes sidelink scheduling logic 902 and
destination identification database 903 as may be utilized for performing functions
as described herein. Sidelink scheduling logic 802 may, for example, comprise program
code stored in memory 282 that is executed by controller/processor 280 for providing
respective functionality. Sidelink scheduling logic 902 may provide functionality
including controlling receiving control signaling from a base station scheduling resources
for a sidelink between the UE and a specified second UE, implementing the sidelink
between the UE and the specified second UE based on the control signaling and in accordance
with the scheduling, etc., as may utilize destination identification information from
destination identification database 903, as described above.
[0085] Those of skill in the art would understand that information and signals may be represented
using any of a variety of different technologies and techniques. For example, data,
instructions, commands, information, signals, bits, symbols, and chips that may be
referenced throughout the above description may be represented by voltages, currents,
electromagnetic waves, magnetic fields or particles, optical fields or particles,
or any combination thereof.
[0086] Components, the functional blocks, and modules described herein (e.g., the components,
functional blocks, and modules in FIG. 2) may comprise processors, electronics devices,
hardware devices, electronics components, logical circuits, memories, software codes,
firmware codes, etc., or any combination thereof. In addition, features discussed
herein relating to scheduling of resources for a sidelink between a first UE and a
specified second UE may be implemented via specialized processor circuitry, via executable
instructions, and/or combinations thereof.
[0087] Those of skill would further appreciate that the various illustrative logical blocks,
modules, circuits, and algorithm steps (e.g., the logical blocks in FIGS. 6 and 7)
described in connection with the disclosure herein may be implemented as electronic
hardware, computer software, or combinations of both. To clearly illustrate this interchangeability
of hardware and software, various illustrative components, blocks, modules, circuits,
and steps have been described above generally in terms of their functionality. Whether
such functionality is implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall system. Skilled artisans
may implement the described functionality in varying ways for each particular application,
but such implementation decisions should not be interpreted as causing a departure
from the scope of the present disclosure. Skilled artisans will also readily recognize
that the order or combination of components, methods, or interactions that are described
herein are merely examples and that the components, methods, or interactions of the
various aspects of the present disclosure may be combined or performed in ways other
than those illustrated and described herein.
[0088] The various illustrative logical blocks, modules, and circuits described in connection
with the disclosure herein may be implemented or performed with a general-purpose
processor, a digital signal processor (DSP), an application specific integrated circuit
(ASIC), a field programmable gate array (FPGA) or other programmable logic device,
discrete gate or transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A general-purpose processor
may be a microprocessor, but in the alternative, the processor may be any conventional
processor, controller, microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a combination of a DSP and
a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction
with a DSP core, or any other such configuration.
[0089] The steps of a method or algorithm described in connection with the disclosure herein
may be embodied directly in hardware, in a software module executed by a processor,
or in a combination of the two. A software module may reside in RAM memory, flash
memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable
disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary
storage medium is coupled to the processor such that the processor can read information
from, and write information to, the storage medium. In the alternative, the storage
medium may be integral to the processor. The processor and the storage medium may
reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the
processor and the storage medium may reside as discrete components in a user terminal.
[0090] In one or more exemplary designs, the functions described may be implemented in hardware,
software, firmware, or any combination thereof. If implemented in software, the functions
may be stored on or transmitted over as one or more instructions or code on a computer-readable
medium. Computer-readable media includes both computer storage media and communication
media including any medium that facilitates transfer of a computer program from one
place to another. Computer-readable storage media may be any available media that
can be accessed by a general purpose or special purpose computer. By way of example,
and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM
or other optical disk storage, magnetic disk storage or other magnetic storage devices,
or any other medium that can be used to carry or store desired program code means
in the form of instructions or data structures and that can be accessed by a general-purpose
or special-purpose computer, or a general-purpose or special-purpose processor. Also,
a connection may be properly termed a computer-readable medium. For example, if the
software is transmitted from a website, server, or other remote source using a coaxial
cable, fiber optic cable, twisted pair, or digital subscriber line (DSL), then the
coaxial cable, fiber optic cable, twisted pair, or DSL, are included in the definition
of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc,
optical disc, digital versatile disc (DVD), hard disk, solid state disk, and blu-ray
disc where disks usually reproduce data magnetically, while discs reproduce data optically
with lasers. Combinations of the above should also be included within the scope of
computer-readable media.
[0091] As used herein, including in the claims, the term "and/or," when used in a list of
two or more items, means that any one of the listed items can be employed by itself,
or any combination of two or more of the listed items can be employed. For example,
if a composition is described as containing components A, B, and/or C, the composition
can contain A alone; B alone; C alone; A and B in combination; A and C in combination;
B and C in combination; or A, B, and C in combination. Also, as used herein, including
in the claims, "or" as used in a list of items prefaced by "at least one of" indicates
a disjunctive list such that, for example, a list of "at least one of A, B, or C"
means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any of these in
any combination thereof.
[0092] The previous description of the disclosure is provided to enable any person skilled
in the art to make or use the disclosure. Various modifications to the disclosure
will be readily apparent to those skilled in the art, all of these falling within
the scope of the following appended claims.